Resistance.



fit zzi-ak- Maw R. MILLER, JR.

RESISTANCE.

APPLICATION FILED JAN. 7, 1910 LO21,256 I latented Mar. 26, 1912.

ance

Low res 4- High sisfance m &1 HUBEHI MILLER JR.

Hi5 ATIJEVEX UNITED STATES PATENT OFFICE.

ROBERT MILLER, JR, OF.SCHENECTA DY, NEW YORK, ASSIGNOR TO GENERALELECTBIQ COMPANY, A CORPORATION OF NEW YORK.

nnsrsranclii.

Specification of Letters I'atent.

Patented Mar. 26, 1912.

' To all whom it may concern:

Be it known that 1, ROBERT MILLER, J r., a citizen of the United States,residin at- Schenectady, county of Schenectady, tate of New York, haveinvented certain new and useful Improvements in Resistances, of

which the following is a specification.

,My invention relates to resistances for electric circuits, particularlyresistances used as shunts in connection w1th various electricaldevices, such as measuring instruments, and'the object of my inventionis to provide a simple and rugged resistance device or shunt of highefficiency, which has a lower operating temperature than shuntsheretofore used and which may be easily and quickly calibrated andadjusted to vary the ohmic resistance of the device.

In accordance with my inventiomnthe-"re sistance or shunt is formed of-meta1 wires or strips of any desired shape interlaced or otherwisesuitably arranged to form a network or gauze having numerous meshesthrough which air or other cooling fluid may circulate freely andthereby maintain the temperature of the resistance within the desiredlimits. The wires or strips which constitute the network may be arrangedin any desired manner so long as they are in contact or in good thermalrelation and form an open mesh structure suit-ably positioned so thatair or other cooling fluid may flow freely over and through it. Theohmic resistance of the resistance device or shunt may be varied and'theshunt calibrated by varying the conducting capacity of any of the wires,or by shiftingthe cross wires with reference to the longitudinal wires.In the preferred construction high resistance wires are strung parallelto each other. in the same plane while transverse wires are strung on amovable support so as to be in good thermal and electr1cal en agementwith the high resistanc wires, so t at adjusting the movable upportmoves all the transversewires simultaneously to vary the angle betweenthem and the high resistance wires, thereby varying the ohmic resistanceof the device. My invention will best be understood in connection withthe accompanying drawing which shows merely for purposes of illustrationone of the forms in which my invention may b embodied and in which-Figure 1 is a plan yiew of an adjustable resistance or shunt and Fig. 2an end view of the adjustable resistance shown in Fig. 1, with a rtionbroken away to show the relation 0 the transverse wires to thelongitudinal high resistance wires.

I have shown one form of adjustable do;

vice embodying my invention comprising a.

suitable base 1 carrying metallic terminals 2 between which a series ofbridges 3 of insulating material are mounted, and between which,longitudinal wires 4 of any suitable in h resistance metal are strungover the bridges 3. The transverse wires 5, which are of copper or anyother suitable heat conducting material, are so related to thelongitudinal wires 4 as to form an open mesh network, and may be mountedin any suitable way which will bring'them into good thermal relation tothe high resistance. wires, 'so that the transverse wires" form"electrical oonnecs tions bet-ween the longitudinal wires and alsorapidly conduct the heat away from them. The transverse wiresmay beloosely interlaced with the longitudinal wires, if dies sired, but inthe preferred construction the longitudinal wires are all mounted in thesame plane. while the transverse wires 5 are strung in firm engagementwith the longitudinal wires and over insulating bridges 6 mounted on amovable metallic support 7,

which is provided with a handle 8 and is pivotally secured to' the base1 by means of a'stud or pivot 9. All of the wires 5 may besimultaneously moved with reference to the longitudinal wires byshifting the adjustable support 7. When the adjustable support is in theosition shown in Fig. 1,- the .resistanceo the device is the maximum; asthe adjustable support is turned about the pivot '9 the angle betweenthe transverse wires 5 and the resistancewires 4 becomes more and moreacute, and at the same time the ohmic resistance between terminals 2decreases, until finally when the wires 5 are substantially parallel to.the resistance wires 4 the ohmic resistance of the device is a minimum,By means of this construction the ohmic resistance may be increased ordecreased in a uniform manner instead of by steps, as, in many forms ofadjustable resistance heretofore used. I I

My invention may be embodied in many other forms than that shown anddescribed, and I do not limit it to the precise arrangement disclosed,but intend to cover by the appended claims all forms and modificationswithin the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,-

1. In an adjustable resistance, the combination with longitudinal highresistance wires of transverse heat conducting wires adjustably mountedin good thermal relation to said longitudinal wires to form a networkand to be adjustable to vary the angle between said longitudinal. wiresand said transverse wires.

2. An adjustable resistance comprising wires arranged tofformanetwork-in which the wires may at will be adjusted with referenee to oneanother.

3. An adjustable resistance comprising longitudinal wires, supports forsaid longitudinal wires, and transverse wires loosely arranged withreference to said longitudinal wires toform a network in which the anglebetween each transverse wire and the longitudinal wires may be varied atwill.

.4. An adjustable resistance comprising wires of different metalsarranged to slide over each other and to form a network in whichthewires are relatively adjustable.

5. In an adjustable resistance, the combination with longitudinal wires,of transverse wires mounted in sliding engagement 'with saidlongitudinal wires to form a network and to be adjustable with referenceto said longitudinal wires whereby the angle between said transverse andsaid longitudinal wires may be varied at will.

6. An adjustable resistance comprislng N wires of manganin andtransverse wlres of copper mounted to engage said manganin strips toform a network and to slide over 4 said strips to vary the angle betweensaid manganin stri s and said copper wires.

7. In an ad ustableresista-nce, the combi. nation with resistance wires,of transverse wires'movably mounted in engagement with said resistancewires, and means for simultaneously moving all said transverse wiresrelatively to saidresistance wires.

8. An adjustable resistance comprising longitudinal wires of highresistance metal,

a support for holding sald wires in position to permit free access ofair, a second support ad ustably mounted with relation to saidresistance wires, and cooperating wires mounted on said second supportto engage said

